The present invention relates to a braking device particularly usable for skates that include a shoe which is composed of a quarter that is articulated to a shell which is in turn associated with a supporting frame for two or more wheels.
In conventional roller skates, whether constituted by a shoe associated with a support for two pairs of mutually parallel wheels or constituted by a Shoe associated with a supporting frame for one or more aligned wheels, there is the problem of braking said wheels in order to be able to adjust the speed of said skate.
It is thus known to use suitable blocks or pads, usually made of rubber, which are arranged at the toe or heel region of the shoe; when the user tilts the shoe backward or forward, the free end of the blocks or pads interacts with the ground and a braking action is thus achieved.
However, these solutions are not optimum, as they require the user to rotate the shoe, and thus the frame associated therewith, at the toe or at the heel, and this can cause loss of balance with consequent falls.
U.S. Pat. No. 1,402,010 discloses a roller skate that has a band which can be secured on the user's leg above the malleolar region and to which a rod is connected.
Said rod surrounds the leg to the rear and is then curved so as to laterally affect said leg until it is associated at its ends, in the malleolar region, with a lever system that is articulated to a flap that protrudes from the wheel supporting frame.
Said lever system protrudes to the rear of the frame and is connected to a plate which is shaped approximately complementarily to the curvature of part of an underlying facing wheel.
This solution is not free from drawbacks: first of all, it produces relative movement between the band and the leg throughout sports practice, and this does not make it comfortable to use.
The plate is furthermore activated every time the user bends his leg backward beyond a given angle, with no true and easy possibilities of varying this condition.
As each user also has a different leg shape, braking is thus achieved at different rotation angles for an equal rod length.
Said rod furthermore acts and presses in the malleolar region, and this can cause discomfort or accidental impacts. Finally, considerable wheel wear is observed.
U.S. Pat. No. 4,275,895 is known as a partial solution to this drawback, and discloses a brake for skates having two pairs of mutually parallel wheels which acts at the rear wheels.
Said brake is constituted by a flap which is associated with the shoe at the rear; a lamina is associated with said tongue in a rearward position and is pivoted at the supporting frame for the shoe.
Said lamina has, at its free end, a transverse element on which two C-shaped elements are formed at the lateral ends; following a backward rotation imparted to the flap, said C-shaped elements interact with the rolling surface of the rear wheels that face them.
Even this solution, however, has drawbacks: it is in fact structurally complicated and thus difficult to industrialize; it furthermore entails the presence of suitable springs that allow to return the flap to the position in which the two C-shaped elements do not interact with the wheels, and this further increases structural complexity.
Furthermore, the structural configuration of the brake causes the two C-shaped elements to interact with the wheel even upon a minimal backward rotation imparted to the flap, and thus even for involuntary movements; this produces unwanted braking actions and thus possible loss of balance or lack of coordination.
Finally, interaction of the C-shaped element at the rolling surface of the wheels leads to rapid wear of said wheels and thus to non-optimum rolling which necessarily entails continuous wheel replacement.
U.S. Pat. No. 4,300,781 discloses a braking device for skates that comprise pairs of mutually parallel wheels.
Said device thus includes a brake which is constituted by a lamina that is transversely pivoted at the rear end of the supporting frame for a shoe; pads which face the rolling surface of the pair of rear wheels are associated with the ends of said lamina.
The brake is activated by using a cable which is suitable to rotate the lamina, in contrast with a spring associated with the support for the pair of front wheels, so as to move the pads into contact with the rolling surface of the pair of rear wheels.
The cable can be activated by means of rings or handles associated with a band which can be arranged on the lower limbs of the user by virtue of the presence of temporary connection means.
However, this solution has considerable drawbacks: first of all, brake activation can lead to possible loss of coordination during sports practice, as the user must perform an uncoordinated movement.
Furthermore, when traction is applied to the rings the band may disengage from the lower limbs, thwarting the braking action.
In any case there is a loose cable which can accidentally catch during skating, especially because coordination of the arm-legs movement places the legs rhythmically laterally outward.
As a partial solution to these drawbacks, the same Applicant filed on Nov. 30, 1992 patent application no. TV92A000150 which claims the use of a first rod-like element and of a second rod-like element which are respectively connected to a quarter which is articulated to a shell connected to a wheel supporting frame and to a braking element, which is oscillatably articulated to said frame and selectively interacts with the ground when a backward rotation is applied to the quarter; at least one first elastically deformable is interposed between the first rod-like element and the second rod-like element.
Although this solution is undoubtedly valid, it has drawbacks; the use of a first rod-like element and of a second rod-like element in fact entails, due to the intrinsic rigidity of said elements, possible accidental impacts thereof during use of the skate.
It has in fact been observed that in case of accidental impacts, for example in a direction at right angles to the longitudinal axis of the first and second rod-like elements, one or both elements can brake or become deformed, consequently altering or thwarting the braking action.
These impacts can occur, for example, against steps that are provided around skating rinks or to delimit sidewalks.